Themes Ubuntu

Gnome Tweak Tool
$sudo apt-get update
$sudo apt-get install gnome-tweak-too

Numix Bluish Theme
$sudo add-apt-repository ppa:noobslab/themes
$sudo apt-get update
$sudo apt-get install numix-bluish-theme

Elegance Colors Theme
$sudo add-apt-repository ppa:satyajit-happy/themes
$sudo apt-get update
$sudo apt-get install gnome-shell-theme-elegance-colors

Paper Theme
$sudo add-apt-repository ppa:snwh/pulp
$sudo apt-get update
$sudo apt-get install paper-gtk-theme